In this experiment concentrated ammonium hydroxide is used t

In this experiment, concentrated ammonium hydroxide is used to prepare the amide derivative of the unknown carboxvlic acid. Whv is it necessarv to use concentrated (15 M) ammonium hydroxide ? What might happen if a less concentrated solution of ammonium hvdroxide (e.g. 1M) was used?

Solution

In the process of amide formation from acid in presence of ammonium hydroxide, first the ammonium salt of the acid is formed which upon heating dehydrates and gives the amide derivative of the acid.

The reaction between ammonium hydroxide and acid to form acidic salt of ammonia is reversible and when low concentrated solution of ammonium hydroxide is used then reversible reaction may take place to give acid back .

Hence to avoid this back reaction ,high concentrated solution of ammonium hydroxide is used ,so that equilibrium shifts in forward direction acc. to Le-Chatlier principle and ammonium salt of acid get formed.